A demand exists for meat substitutes which are nutritionally equal to or better than meat, but which are not as costly. In response to this demand, several protein products have been developed and are available commercially for use in foods. Vegetable proteins are available as flours, concentrates, isolates, and in various textured forms well known in the art. Use of textured proteins in food products as meat substitutes or meat extenders is desirable to provide consumers with convenient low-cost nutritious meals.
Unfortunately, obstacles exist to greater use of textured proteins in food for human consumption. Deficiencies in product flavor, texture, and appearance can result in poor consumer acceptability. Product color is important to consumer preference of foods. For tomato products, consumers associate a redder, darker color with optimum maturity of the raw product and consequently with better flavor. Conversely, a browner product may indicate the use of less mature raw material which would impart a bitter taste. Degradation of red color could also be due to improper processing or storage, or to product spoilage. Color standards exist for raw tomatoes as well as for several processed tomato products.
In tomato products containing textured protein, the protein should have the brown colors of meat. Textured protein materials lack the brown color of cooked meats. Use of colorants with textured proteins is not always effective due to color leaching in the presence of water. U.S. Pat. No. 3,925,561 of Herstel et al., issued Dec. 9, 1975, discloses use of a C.sub.5 sugar or phosphate ester of a C.sub.5 sugar to color vegetable protein dark brown in a manner such that the color does not leach out when the protein comes into contact with water during later rehydration, cooking or processing.
Products containing textured protein are known in the art. U.S. Pat. No. 3,961,083 of Coleman, issued June 1, 1976, discloses a textured vegetable protein product which can be mixed with seasonings to prepare a barbecue meat-like product for use in sloppy joes, chili, and the like. No color ranges are defined for these products. A process for producing product of optimal color or for rendering the barbecue product storage stable is not disclosed. This lack of attention to product color is likely to contribute to an absence of widespread use of such products.
It has now been found that the production of a shelf-stable tomato-based sauce product containing textured protein using conventional processing techniques can result in product of an undesirable color. Retort processes, high-temperature-short-time commercial sterilization, and hot-fill-hold packing techniques are well known in the processing of tomato products. Application of these processes in the manufacture of tomato products containing textured protein often results in product of poor color quality. It is desirable to have shelf-stable tomato sauce products of acceptable color containing textured protein in order to provide the consumer with an appetizing and nutritious substitute for the meat-containing products currently available.
It is therefore an object of the present invention to provide a tomato-based sauce product containing textured protein having an optimal color acceptable to consumers.
It is a further object of the present invention to provide a tomato-based sauce product containing textured protein which is shelf stable.
It is a further object of the present invention to provide a process for the preparation of a shelf-stable, tomato-based sauce product containing textured protein.
It is a further object of the present invention to provide a process for the preparation of a shelf-stable, tomato-based sauce product of acceptable color containing textured protein.
These and other objects of the invention will be obvious from the following descriptions and examples.